In Vitro Inhibition of Pathogens by Polyols: Optical Density-Based Screening and Implications for the Oral-Systemic Axis.

Polyols are widely used as non-cariogenic sweeteners in foods and oral care products, yet their comparative activity against diverse oral microbes and their potential relevance to the oral-systemic axis remain incompletely defined. Here, we performed an in vitro, optical density (OD)-based screening of four polyols-allulose, D-mannose, erythritol, and xylitol-against Streptococcus mutans, Streptococcus anginosus, Candida albicans, and Fusobacterium nucleatum. Cultures were grown with polyols at 1-20% (w/v), and OD600 was recorded at organism-specific endpoints (~24 h). Allulose, erythritol, and xylitol produced strong, concentration-dependent suppression of streptococcal growth at ≥5-10%, whereas C. albicans showed minimal changes across the tested range. F. nucleatum was highly sensitive to allulose, D-mannose, and xylitol at ≥5% (reducing OD to ≤13% of the untreated control), while low concentrations of D-mannose and erythritol increased OD beyond that of the control, suggesting species-specific utilization or stress responses. One-way ANOVA with Tukey's HSD post hoc testing supported significant between-polyol differences for most concentrations in Streptococcus spp. and F. nucleatum. Collectively, these results identify polyol- and taxon-specific growth phenotypes that can inform the formulation of swallow-safe oral hygiene products and motivate follow-up work in polymicrobial biofilm models and clinical studies targeting oral inflammation and downstream systemic risk.